Data Analysis Books | Python | SQL | Excel | Artificial Intelligence | Power BI | Tableau | AI Resources
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显示更多📈 Telegram 频道 Data Analysis Books | Python | SQL | Excel | Artificial Intelligence | Power BI | Tableau | AI Resources 的分析概览
频道 Data Analysis Books | Python | SQL | Excel | Artificial Intelligence | Power BI | Tableau | AI Resources (@learndataanalysis) 英语 语言赛道中的 是活跃参与者。目前社区聚集了 51 874 名订阅者,在 教育 类别中位列第 3 351,并在 印度 地区排名第 7 142 位。
📊 受众指标与增长动态
自 невідомо 创建以来,项目保持高速增长,吸引了 51 874 名订阅者。
根据 19 六月, 2026 的最新数据,频道保持稳定运转。过去 30 天订阅人数变化为 476,过去 24 小时变化为 7,整体触达仍然可观。
- 认证状态: 未认证
- 互动率 (ER): 平均受众互动率为 4.68%。内容发布后 24 小时内通常能获得 1.17% 的反应,占订阅者总量。
- 帖子覆盖: 每篇帖子平均可获得 2 430 次浏览,首日通常累积 609 次浏览。
- 互动与反馈: 受众积极参与,单帖平均反应数为 4。
- 主题关注点: 内容集中在 analyst, |--, excel, visualization, analytic 等核心主题上。
📝 描述与内容策略
作者将该频道定位为表达主观观点的平台:
“Data Analysis Useful Resources
#dataanalysis
#dataanalysisbooks
#sqlbooks
#pythonbooks
#tableau
#powerbi
#datavisualization
For promotions: @coderfun”
凭借高频更新(最新数据采集于 20 六月, 2026),频道始终保持新鲜度与高覆盖。分析显示受众积极互动,使其成为 教育 类别中的关键影响点。
GFGWINTERARC for 25% OFF (Limited Time!).dropna(), .fillna() functions to do this easily.
4. What are list comprehensions and how are they useful?
Concise syntax to create lists from iterables using a single readable line, often replacing loops for cleaner and faster code.
Example: [x**2 for x in range(5)] → ``
5. Explain Pandas DataFrame and Series.
⦁ Series: 1D labeled array, like a column.
⦁ DataFrame: 2D labeled data structure with rows and columns, like a spreadsheet.
6. How do you read data from different file formats (CSV, Excel, JSON) in Python?
Using Pandas:
⦁ CSV: pd.read_csv('file.csv')
⦁ Excel: pd.read_excel('file.xlsx')
⦁ JSON: pd.read_json('file.json')
7. What is the difference between Python’s append() and extend() methods?
⦁ append() adds its argument as a single element to the end of a list.
⦁ extend() iterates over its argument adding each element to the list.
8. How do you filter rows in a Pandas DataFrame?
Using boolean indexing:
df[df['column'] > value] filters rows where ‘column’ is greater than value.
9. Explain the use of groupby() in Pandas with an example.
groupby() splits data into groups based on column(s), then you can apply aggregation.
Example: df.groupby('category')['sales'].sum() gives total sales per category.
10. What are lambda functions and how are they used?
Anonymous, inline functions defined with lambda keyword. Used for quick, throwaway functions without formally defining with def.
Example: df['new'] = df['col'].apply(lambda x: x*2)
React ♥️ for Part 2SELECT department, AVG(salary)
FROM employees
WHERE salary > 3000
GROUP BY department
HAVING AVG(salary) > 5000;
2. Write a query to find the second-highest salary.
Solution:
SELECT MAX(salary) AS second_highest_salary
FROM employees
WHERE salary < (SELECT MAX(salary) FROM employees);
3. How do you fetch the first 5 rows of a table?
Solution:
SELECT * FROM employees
LIMIT 5; -- (MySQL/PostgreSQL)
For SQL Server:
SELECT TOP 5 * FROM employees;
4. Write a query to find duplicate records in a table.
Solution:
SELECT column1, column2, COUNT(*)
FROM table_name
GROUP BY column1, column2
HAVING COUNT(*) > 1;
5. How do you find employees who don’t belong to any department?
Solution:
SELECT *
FROM employees
WHERE department_id IS NULL;
6. What is a JOIN, and write a query to fetch data using INNER JOIN.
Solution:
A JOIN combines rows from two or more tables based on a related column.
SELECT e.name, d.department_name
FROM employees e
INNER JOIN departments d ON e.department_id = d.id;
7. Write a query to find the total number of employees in each department.
Solution:
SELECT department_id, COUNT(*) AS total_employees
FROM employees
GROUP BY department_id;
8. How do you fetch the current date in SQL?
Solution:
SELECT CURRENT_DATE; -- MySQL/PostgreSQL
SELECT GETDATE(); -- SQL Server
9. Write a query to delete duplicate rows but keep one.
Solution:
WITH CTE AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY column1, column2 ORDER BY id) AS rn
FROM table_name
)
DELETE FROM CTE WHERE rn > 1;
10. What is a Common Table Expression (CTE), and how do you use it?
Solution:
A CTE is a temporary result set defined within a query.
WITH EmployeeCTE AS (
SELECT department_id, COUNT(*) AS total_employees
FROM employees
GROUP BY department_id
)
SELECT * FROM EmployeeCTE WHERE total_employees > 10;
Hope it helps :)
#sql #dataanalysts
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